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Regulation of Na+/K+ ATPase transport velocity by RNA editing.

ABSTRACT: Because firing properties and metabolic rates vary widely, neurons require different transport rates from their Na(+)/K(+) pumps in order to maintain ion homeostasis. In this study we show that Na(+)/K(+) pump activity is tightly regulated by a novel process, RNA editing. Three codons within the squid Na(+)/K(+) ATPase gene can be recoded at the RNA level, and the efficiency of conversion for each varies dramatically, and independently, between tissues. At one site, a highly conserved isoleucine in the seventh transmembrane span can be converted to a valine, a change that shifts the pump's intrinsic voltage dependence. Mechanistically, the removal of a single methyl group specifically targets the process of Na(+) release to the extracellular solution, causing a higher turnover rate at the resting membrane potential.

SUBMITTER: Colina C

PROVIDER: S-EPMC2990702 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature

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Regulation of Na+/K+ ATPase transport velocity by RNA editing.

Colina Claudia C Palavicini Juan Pablo JP Srikumar Deepa D Holmgren Miguel M Rosenthal Joshua J C JJ

PLoS biology 20101123 11

Because firing properties and metabolic rates vary widely, neurons require different transport rates from their Na(+)/K(+) pumps in order to maintain ion homeostasis. In this study we show that Na(+)/K(+) pump activity is tightly regulated by a novel process, RNA editing. Three codons within the squid Na(+)/K(+) ATPase gene can be recoded at the RNA level, and the efficiency of conversion for each varies dramatically, and independently, between tissues. At one site, a highly conserved isoleucine ...[more]

PMID: 21124885

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